*[Moderator's Note: Thread spun off from previous discussion.]*

MWI and the TSVF are both easily generalized to QFT. One only needs to define the decoherence basis for the fields (see https://arxiv.org/abs/quant-ph/9510021) and then one simply interprets the decoherent histories as ontological worlds. The advantage of the TSVF is having a simple way of introducing the Born Rule as an axiom, ie placing the future boundary to prefer one decoherent history through a Born weighted random choice makes the "chosen/real" world overwhelmingly likely to have typical quantum statistics.I didn't say that retrocausal theories can't get out the statistics, I said they aren't generalized to QFT fully, neither is the TSVF you are discussing. Kastner's work can be considered to have shown that it might be able to replicate aspects of QED, but I'm not aware of a full proof that it works in the QFT case.

Many Worlds has many issues with QFT, such as the absence of pure states for finite volume systems. And the Born rule has never been proven to hold

The Reeh Schlieder/Von Neumann Type 3 issue you allude to is also not really a problem for these interpretations. Rather, this is an issue for Copenhageners who want to represent measurement by projection operators on local algebras. There are no local projections at all in MWI or TSVF.